LCD input Lag problems: new tests of 2405fpw and 244t

Hey guys, try turning of V-sync. It will take away the input lag, but you will get minor tearing. If you can set you refresh at 75hz it might not bother you. I find this much better for gameplay.
 
Vsync is not the issue. You are refferring to "triple buffering" which is a technology that allows the graphics card to work ahead on frames when it is being underused. The input lag we are noticing and discussing happens on the desktop also, which means it is not vsync. (And i never use vsync anyway.)
 
disabling vsynch actually did quite a lot to solve the problem on my rig, can't beleive I missed that. In counterstrike now at least, the lag is no longer a showstopper. In quake3 the problem is more easily apparently but not crippling as it was with vsynch enabled. I agree that this isn't the main issue though, the lag is still there and in windows my logitech g7 feels like a serial mouse.
 
Try this: I put my aluminum mouse pad and mouse (Razer Copperhead) right up to the screen and adjusted the sensitivity so the cursor and mouse movements are about the same. I can see no hint of any kind delay that the 2405 would be causing. As soon as my hand and mouse move the cursor moves along with it and stops with it. Even if tap the side of the mouse both the mouse and cursor move exactly together, as best my human eye can see. We all know that logically there is some delay but I can’t see it.
 
suggestions of video output settings or mouse calibrations are, I'm sure, well intentioned but miss the point. He has a SIPS and SPVA panel sitting side by side on the same machine and one (SPVA) is exhibiting a delay versus the other (SIPS). In this case the larger panel is not showing any input lag. What we don't know is if this is inherent with the panel specifically and therefore a problem with the technology or a problem with a specific model of monitor and therefore a problem with that implementation.

Other than the upcoming 2407, are there any other monitors out there that use the same panel as the 244t?

This is now uber important as dell is thinking of ditching the panel it uses in the 3007, which is sips, and going to a spva panel. it also means that the gamers should stick with older 23" sips panels instead of monitors based on the panel in the 244t. it puts upgrade paths into question, so it's a pretty damn big deal.
 
You missed my point. If the mouse moves right when the cursor does and the cursor stops right when the mouse does, where's the lag? Using two LCD on the same PC is problematic. You don’t know how the card is rendering the two displays even if cloning.
 
Well I can backup the OP with the comments on the input lag. I purchased and received an Acer 24" which is supposed to use the exact same panel as the 244T. I posted in my thread concerning the issue, and it is very real. Moving the mouse around the desktop is absolutely terrible.

At first I thought, these are the latest panels and boast extremely high refresh rates and have amazing specs, theres no way there could be anything wrong. Unfortunately I was let down, and this is definitely a MAJOR issue. If the screen was 500 and 24" and had the same specs, there would be no room to complain. But for prices ranging from 900-1300 for the 244t and Acer, its not worth it.

If the upcoming Dell is going to have the same panel as these two, that could be definitely a problem. However, I believe that they would be sure to avoid making a huge mistake such as this and try to figure out a way to release an updated 24" w/o the lag.

I'm going for the 23" Apple Cinema tomorrow, paying the extra price to buy from a store and look for a better screen.
 
Hi I have a 2405, its my first lcd, and its an awesome monitor until I try playing ut2k4 or any game that has hitscan.... the monitor is so lagged. Everything 'feels' wrong, I can't even play on the dell. I've been using a 15" crt when I want to play games which is pretty sad.

Anyways is this 'lag' unique to these larger panels? I'm not sure if I should just go get a cheap 19" crt for gaming or try some of the new real fast lcds. Viewsonic's VX924 claims 3ms responce... is there any other lag assoicated with this type of display? I don't want to have to deal with any detectable lag... should I just get a crt and be safe?

I just used the vx924 as an example is there anything better in terms of minimal lag?
 
Quick update - I was running the 3007 and 244T ona 7800 512MB which only had one dual link DVI port, so I couln't swap the monitors around to eliminate the "slow dvi port" factor. I've now swapped in an X1900 XTX with two dual link ports and I've run the 244T off both ports. The lag is completely consistent no matter which port is used is whether in dual or sinlge monitor mode. The 244T is fubar, plain and simple.
 
this is looking more and more like a PVA panel (Acer, DELL & Samsung) issue as IPS panels dont have the lag. Looks like a 23" AS-IPS LCD monitor would really change things, Apple is updating the 30" for sure, maybe the rest of the family will be updated.
 
I just got a 2405FPW (version A05) and the input lag is very real and easily noticable. I am getting my arse kicked in UT and UT2K4 since I got it. Just dragging a window up and down between it and a Sony 19'' (G400) shows huge lag. I found that disabling VSync helped quite a bit in games (not for desktop though) but didn't make it completely go away. Also, it's annoying me a bit (not sure why, maybe it's the backlight). But the monitor is sharp and bright! I am not sure whether I want to keep it. The real question is: are there any LCDs that don't exibit this input lag? Is there a way around it or are we stuck with CRTs? The Dell is so much sharper than the Sony it's not even funny. I tried upping the refresh to 75 Hz but the monitor is saying it's an unsupported mode. How do you do this with an NVidia card?

Just looked at another thread with a guy who bought a FW900 (24'' wide CRT) and now I'm thinking of doing the same thing except it's a pain to buy these thnigs, CRT can easily have defects.
 
I've tried several 23"/24" monitors, including the Dell 2405FPW and the Samsung 244T, and I had a similar experience.

Not all LCD monitors lag that badly. Based on my own testing, I've found that the 23" Apple Cinema Display has virtually no lag when compared side by side with a CRT running at 60 Hz while the Dell and the Samsung lag way behind. The difference is laughable.
 
HP L2335 and Dell 3007WFP are both lag free large LCD monitors. I think we've pretty much established that the problem only effects PVA panels for whatever reason.

I believe NEC are about to launch a 23-inch AS-IPS monitor, that could well trun out to be the best monitor in the 23-24-inch space.
 
I'm thinking about the Apple but also, what about the upcoming Dell 2407FPW? Is that going to be OK? It's strange that the 30'' monster is lag free while the 24'' lags so bad.
 
2407 probably will be laggy. The reason the 30-incher doesnt lag is almost defintiely because it uses an S-IPS panel. All the laggy monitors have PVA panels.
 
If I may act like the total noobie...

After having read through this thread, I must say that I am rather worried. I have a Samsung 242MP on order, and from the specs page it is a PVA monitor. Does anyone have any experience with this monitor?

As I understand it, the issue here is input lag, rather than the standard 'ghosting' problem which LCDs have traditionally faced, which can be improved based on the response time. This input lag only affects large sized LCDs - anything larger than 23". I currently have a Gateway FPD2185W and as far as I can tell, I don't experience any input lag. I don't have any fancy setup to test this, but using the simple 'move-mouse-until-cursor-stops' test I can say that the cursor stops as soon as I stop my mouse, or soon enough that my poor human reflexes cannot tell the difference. I do not play any FPS games so perhaps the issue will show up there though.

Nevertheless - anyone with a 23-24" LCD that *doesn't* experience this issue? Is it based largely on individual perception (I would say that as far as reflexes go, I'm on the slow end) or does it affect everyone?
 
caboosemoose said:
I believe NEC are about to launch a 23-inch AS-IPS monitor, that could well trun out to be the best monitor in the 23-24-inch space.
Click to expand...

NEC are being very tight lipped about this, they havent answered numerous emails about the 23" version while I did get a response about the 20".

The 23" AS-IPS panel is available in quantity, the latest Philips 23" uses the the panel however its a business version and hence doesnt have the DVM option to boost the contrast ratio.
 
How do you even contact those big companies? I mean the most data they would gather from their users so they can imporve their products, and both Dell and Samsung obviusly made a mistake on their screens, or neglected to explain how to use them, so how do you tell them that? They must have some customer support other than your dealer where you bought the products. I mean I know those are huge companies and they had to decentralize their customer support, but still, is there a way to get through them and ask about this input lag in 244t?
 
I still cannot handle how games feel on my new Nec 20" lcd compared to my FW900. Any resolution I feed into the NEC doesn't stand up to the FW900 in feel. V-Sync doesnt feel silky smooth, I swear that there is some tearing here and there. Now this I am sure of : DVD playing shows a decent amount of tearing across DVI. I dind't see tearing while running a Viewsonic 2025wm on Analog VGA next to the Nec which was running DVI. WHY IS THIS? Something with my config? Card? Thanks!!
 
Reviving this excellent thread to add some observations about input lag on other non-VA type panelled LCDs, from the perspective of someone who plays fast fps games and has noticed input delay while gaming on more than one LCD.

Recently I borrowed a Samsung 204B and found the lag to be a significant problem, especially when aiming precision weapon in the thick battle in UT2004 and other fast games. I researched the topic a bit and found the test methods for input lag here so I started my own informal testing. Unsurprisingly, the 204B had 35-40ms+ latency in comparison with my Samsung 900IFT CRT monitor using the clone-mode-stopwatch method. Maybe this explains why playing offline with fps games felt like I was online with a mediocre connection. Take note: this is very noticeable lag on an LCD with a fast TN panel.

I also tried and tested the Viewsonic VX922 but unfortunately my findings were inconsistent so I hesitate to say anything. Subjectively I felt there was some noticeable but minor lag (nothing like the 204B) in comparison with the CRT but in testing I measured consistently fairly low latency averaging 15-20ms. I have another few hours with this monitor so maybe my subjective impression will change, but for now I am inclined not to keep this it (I am also not thrilled with the washed out colours and difficulty finding acceptable brightness/contrast and color settings).

Finally I also tried the new LG 1970HR, also with TN panel, but which reportedly has no 'overdrive' technology according to a review at chip.de (I find this hard to believe since LG is claiming '2 ms' RT). Subjectively I detected no noticeable lag on the 1970HR whatsoever and found it almost as good as my CRT, apart from the obvious LCD limitations: lower frame rate cap with vsync on, unbearable tearing with vsync off, and some typical but non-intrusive LCD motion blur (no ghosting that I noticed). I measured low latency in tests against my CRT, in the range of 15-20ms.

Conclusions: as some have remarked, it is really unacceptable that otherwise thorough hardware review sites (tomshardware.com, prad.de, hardware.fr) reviewing 'gaming' LCD monitors are not taking input lag seriously and attempting to measure it on units they review. I may be in the minority as a player of fast fps games, but my experience with 5 or 6 recent LCDs in the past is that ghosting and motion blur is getting to be a relatively MINOR problem despite the being the preoccupation of reviewers. On the other hand I've found input lag is a real and significant problem with no official attention being paid to it and no manufacturer specifications (comparable to response time used to predict ghosting, etc.) to guide consumer purchases. In the case of my own purchasing decision, I still want to try an LCD with IPS so if I find one to test I will report back. I am not holding my breath that an IPS panel (or any panel technology) 'solves' the problem either, since I have seen complaints online of input lag on the Dell 2001FP, for example, and one web site tracking input lag using a different methodology reports a 55-76ms latency with the 2001FP: http://www.draebenstedt.de/reaction/loopback.html.

Questions: (1) What are the implications of using a less fast digital camera apart from possibly needing to sort through more unusable photos? I mean, if you capture legible digital stopwatch readouts on both the CRT and LCD screens the measurement is valid, is it not? (2) How would one explain a photo capturing identical stopwatch time readouts on both screens if digital lag in fact does not fluctaute? Would this be simply an incorrect reading of a botched photo or could it be explained by the 17ms or so inaccuracy due to measurement error/limitation surmised by okashira? (3) How does vsync affect perceived lag? I felt there was less lag with vsync off on my 204B but tearing was severe, and I noticed that testing at the above this site again shows higher latencies with vsync on: http://www.draebenstedt.de/reaction/loopback.html.

We really need a site to compile input lag measurements for different LCDs...

EDIT: After playing more on the VX922 I not longer subjectively perceive any input lag. I think it didn't feel right before because I first tried the VX922 right after switching video cards to a 6600GT with dual dvi to do some comparative LCD testing, and it turns out I was getting worse frame rates with that card than my normal vid card. I feel better now that subjective perception has come into line with measurements from the objective testing laid out in this thread. :cool:
 
Agreed! And well put. I think I am sending my 2405 back due to lag, its a tough decision but these monitors cost too much money to be sub par.
 
zlvg41.jpg


Ok, I fed the composite video feed from my X1900xtx to my 2405, 2005 and a small Sony CRT. The 2405 and the 2005 were identical using xNote Stopwatch but the CRT was ahead buy a whopping .05 seconds. That’s if I read the n umbers right. After looking at many pictures that I took that’s what I saw over and over again. I’d need a super high speed camera to be sure. It’s hard to tell which numbers it’s moving from or to sometimes.

I also tried DVI to the 2405 and composite to the 2005 and CRT. That put the 2405 closer or about the same as the CRT.

With a digital display I would expect some delay on a very small and otherwise unnoticeable level. The driver chipset in the display has to have some time to do it’s thing. I don’t notice any lag when play CS: Source. Can we humans really see a 5 (or less) hundredth of a second difference?

My Setup: Here
 
Tanquen said:
The driver chipset in the display has to have some time to do it’s thing. I don’t notice any lag when play CS: Source. Can we humans really see a 5 (or less) hundredth of a second difference?

My Setup: Here
Click to expand...

I doubt anyone can detect a delay of 5ms but 50ms is easily detected. And that is the neighborhood of lag measured consistently and subjectively detected on several LCDs. Perception of the lag will of course vary depending on the the application. In fast FPS gaming, as I reported, I detected the input delay on the 204B (measured at up to 40+ms) INSTANTLY and found it unmistakable. In games like UT2004 or Quake, I would say that if you can't detect a 40-50ms lag, then I would be worried. ;)

If the last two numbers of the stopwatch in your photos are of milliseconds then I would be curious why your results are so 'dramatically' different than those of the first poster for the 2405. How did you consistently get a 5ms lag when everyone else notes a variation or fluctuation, possibly due to the measurement error noted by the okashira? Maybe others are better able to comment on your method or measurements.
 
Loque said:
How did you consistently get a 5ms lag
Click to expand...
That stopwatch program only displays up to the hundreds of a second. 5 hundreths = 50ms.
However I see 75 and 81, which means 60ms.

I'm not so sure whether that is correct though, in the CRT it looks to me as though it is an 8 transitionning to a 9 instead of a 7 transitionning to an 8. (If it was 7-->8, the 4 unlit parts of the 7 aren't changing white-->black at the same time, 2 are already solid black, while another is almost still white)
If it is a 9, that means a whopping 160ms delay, which seems unlikely.


The real thing I am getting from the image is that the delay is the same in the 2405 and the 2005, even though one uses a SPVA screen and the other a SIPS.
 
okashira said:
I'm worried that SED and other display tech will have the same problem, it seems to me there is no reason for LCD's to have lag other then then the fact they are digital displays, while crt's are analog.
Click to expand...

I know! I'm so worried. C'moooon SED!
 
Koho said:
The real thing I am getting from the image is that the delay is the same in the 2405 and the 2005, even though one uses a SPVA screen and the other a SIPS.
Click to expand...

The display type being different should mean little. If the actual response time is better on one then the other you would just see less or more blur between certain colors. The display chipset takes in a video feed and decides to tell each element what to change to.

What we are talking about (I think) is the driver chipset in the display getting an image and buffering it too long before sending it on and telling the elements in the display to change to what they need to be to form that image.
 
Tanquen said:
What we are talking about (I think) is the driver chipset in the display getting an image and buffering it too long before sending it on and telling the elements in the display to change to what they need to be to form that image.
Click to expand...
Yes, but obviously different monitors have different delays, the Samsung in the original post has a larger delay than the 2405.
Personally I was planning on getting a 2005WFP, and was hoping this input delay was restricted to the 2405s, but apparantly it is not.
 
I tried upping the refresh to 75 Hz but the monitor is saying it's an unsupported mode. How do you do this with an NVidia card?

You can find it under Screen Reseoution & Refresh Rate then make sure that the box is un ticked next to Hide Modes that this monitor cannot support.

Then goto Custum resolutions and refresh rate, then click on the ADD button and go from there..

I have a GF 6800gt APG and have my 2405FPW contcted through DVIand have custom modes up to 240 Hertz.

I don't why but the higher the Hertz the faster the mouse responds.

Hope this helps
 
Yes but if I look at the OSD on my Dell it displays 60 or 75Hz no mater what. The 60 – 75Hz spec on most LCDs is a synchronizing window. The refresh rate of the LCD panel is for the most part, fixed. You can throw all the fames pre second at it that you want but the chipset in the LCD display is going to grab one each 60th of a second or so and ignore all the rest.

I do agree that some displays are introducing lag but I don’t think most of them have introduced enough to make a difference. I recall paying SIN online back in the day on slow 150-300 ping modems and that was lag. I had to lead shots by a half inch or more sometime but I would adapt and still manage to kick some ass from time to time. Now a lag difference of less then 1 10th (0.1 Seconds) of a second is ruining game play? I have even seen guys say that changing the vertical sync seems to make a difference. But that should not affect this display induced lag. I think its one part (maybe) LCD induced lag and two parts running high res on a big display.

I’ve played on my CRT which test to update 1 10th (0.1 Seconds) or less faster then the LCD and I can’t tell the difference. But that’s just me and my displays.

We need to get someplace like Toms Hardware to take a look. I’ve emailed them how about everyone else send them one?
 
Tanq,

Did you even read the thread? Maybe I missed something someone else was saying but the original thread claims ~50ms delay and all photos and data support this. The 244t sometimes has as much as 80ms delay. This is constant, not variable like network lag and it is not isolated to games since it occurs on the desktop as well.

Where on earth do you get 1ms?
 
docmal said:
Tanq,

Did you even read the thread? Maybe I missed something someone else was saying but the original thread claims ~50ms delay and all photos and data support this. The 244t sometimes has as much as 80ms delay. This is constant, not variable like network lag and it is not isolated to games since it occurs on the desktop as well.

Where on earth do you get 1ms?
Click to expand...

Oops, you got me. Did YOU read the post? <-- That is lame, just ask the question. That is MY pic up a bit but I wish I had a real good hi speed video (like on mythbusters) camera so I could see what is really happening. But it looks like 0.1 to 0.05 seconds. That’s using the composite inputs. If I use the DVI input on the 2405 it’s even closer to the CRT. Also, the fact that the lag is constant is much better than network lag. After finding these post I kinda can feel something sometimes but I pay lost of CS:S and it has not changed anything for me. Mileage may vary.
 
thanks for the reviews, i was about to put my sony 21' crt aside and buy a 2405fpw.
i play alot of fps and the lag will surely get me pwned. thanks
guess ill go pay some bills :)
 
Loque said:
If the last two numbers of the stopwatch in your photos are of milliseconds then I would be curious why your results are so 'dramatically' different than those of the first poster for the 2405. How did you consistently get a 5ms lag when everyone else notes a variation or fluctuation, possibly due to the measurement error noted by the okashira? Maybe others are better able to comment on your method or measurements.
Click to expand...

Because he used the same composite feed split between 3 monitors instead of using 2 seperate DVI ports. This was an attempt to remove the variable that perhaps the card couldn't produce the exact same framerate on each DVI port, thus resulting in what is percieved as input lag.

And if you think about it, he's seeing about a 6ms lag, which is about what the pixel response time it on those monitors (I think it's 6ms on the 244T). So I'd like to say that, yes, in some cases input lag is a felt by the user, but it is not as different in times as the dual DVI screenshots show.

Again, to reiterate. By using the SAME signal split 3 ways he was able to eliminate the variable of 2 sources which are possibly unable to be rendered in sync.
 
As was said in a post shortly after those screens that lag is not 5ms its 50ms, hes using a clock showing accuracy to 100ths of a second not miliseconds eg 0.05 seconds is 50 miliseconds.
 
This is exactly why i choose for an S-IPS screen and 23" instead of 24"..

Very nice review/proof !

I wish there were more like this. And i dont understand why reviewers on like for instance Toms Hardware Guide don't even notice this !!
 
I just purchased a 244t for my home, running off 7900gt sli using DVI. In the limited gaming I've done so far, I haven't noticed too much input lag, but I haven't done any serious FPS gaming yet.

Up at my office I have a 2405 and a 2005 side by side, as well as high speed video cameras (600 frames per second is possible...)

I ran a virtual stop watch program on clone mode. Using DVI for the 2405, vga for the 2005 on a dimension 9150 with x600 video card.

The 2405 noticably lags behind the 2005...

WMV9 Avi File page link

There's a relatively poor video quality video at 100 frames per second up there. I'm trying to decide if its worth comparing the 2405 and 244t side by side (that would involve carrying a monitor somewhere...) I don't own a CRT I can test with anymore either.
 
I just tested Source again yesterday...and finally realized why my "skill" dropped so much, going from my trusty 17" CRT to the 2405. I would move left or right, and there'd by a split second where I wouldn't move on the screen...then I'd move. In terms of aiming, I didn't feel any lag, but strafing or jumping was completely out of question.

That said, is there a 23 or 24" that DOES NOT have this dreaded input lag? It's a damn shame that I can't do any FPS on my 2405. It's like it was made to do only large, 100+ page research papers...lol

*YES, i can have multiple windows of Lexis Nexis up. YES!
 
Sorry. You're right I didn't know how .0 seconds and ms equated.

There are 23" LCDs but their response time is too slow and have ghosting. So its either input lag or ghosting.

Very unfortunate.
 
Sluuut said:
This is exactly why i choose for an S-IPS screen and 23" instead of 24"..

Very nice review/proof !

I wish there were more like this. And i dont understand why reviewers on like for instance Toms Hardware Guide don't even notice this !!
Click to expand...

The panel technology being S-IPS, TN-film or PVA/MVA and this input lag of which we speak are two different things. Depending on the type of LCD panel, there can be large differences in the pixel refresh depending on whether it’s going from black to white, or rom gray to gray. This can cause a burry image or color shift on fast moving images but the overall image (on newer faster displays) is where it needs to be, for the most part. We would all love to see sub ms responses time for all color changes and may well some day soon but that is not the issue here, I think.
 
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